In the past, techniques of performing detection of porphyrins by binarizing an image obtained by extracting a red (R) component from an image photographed by irradiating the skin of the user with ultraviolet (UV) light and then displaying a region in which porphyrins are detected, the number of detected porphyrins, and an area size in which porphyrins are detected have been proposed (for example, see Patent Literatures 1 and 2).